Question

A={1,2,3,4,5,6};How many bijective functions `f:A->A`have the property that `f(1)!=2`?

Answer 1

`600`

Explanation:

A bijective function from a finite set to itself is a permutation.

There are a total of `6!` permutations of `6` objects, of which exactly `1/6` map `1` to `2`.

So the answer is:

`6!*(5/6) = 5!*5 = 120*5 = 600`